Compound resin molding and process for producing the same

ABSTRACT

The object of the present invention is to provide a compound resin mold consisting of solvent soluble and insoluble thermoplastic resin elements and a method for the manufacturing thereof. For example, in a case where said compound resin mold is a printed circuit board, the base board consists of said soluble thermoplastic resin element, with said insoluble elements being the metal thin film circuit and thermosetting resin film formed on said base board.

FIELD OF THE INVENTION

The present invention relates to a compound resin mold consisting of athermoplastic resin elements being solvent soluble and insoluble, and amethod for the manufacturing a resin mold for the purpose of recycling.

BACKGROUND OF THE INVENTION

In the printed circuit boards being used as the electronic parts ofvarious electric appliances and the like, thermosetting resin(s) such asepoxy resin, phenolic resin, melamine resin and the like, to which glassfiber, cellulose fiber, inorganic filler, and the like is(are) add,is(are) used as main material(s).

Said thermosetting resin can not be heat-melted, and is solventinsoluble. Therefore, the recycling of said thermosetting resin moldsuch as said printed circuit board and the like has been difficult. Inparticular, the thin metal film circuit and thermosetting resin film areformed on the surface of said printed circuit board, and glass fiber,cellulose fiber, inorganic filler and the like is(are) contained in saidboard as described above, making the recycling of said printed circuitboard more difficult. Further, heavy metal(s) such as lead, tin and thelike is(are) contained in said board, and still further, in a case wheresaid board is made of an epoxy resin as thermosetting resin, bisphenolA, which is a component of said epoxy resin, acts as an environmentalhormone, so that extreme care is necessary even after the disposing ofsuch a board in the ground. Generally, a halogenide fire retardant suchas a bromide fire retardant, chloride fire retardant and the like areused to give fire retardancy to the resin(s) of which said printedcircuit board is composed, and in the case of incineration or thermalrecycling of said discarded board, it is feared to cause a problem suchas generation of dioxine and the like.

DISCLOSURE OF THE INVENTION

To solve above described problems, the present invention provide acompound resin mold consisting of thermoplastic resin element(s) beingsolvent soluble and having a heat distortion point higher than 80° C.,said point being measured by the method following ASTM D648 and applyinga load 1,820 MPa, and solvent insoluble element(s).

For example, said compound resin mold is a printed circuit board andsaid board is made of said thermoplastic resin element being solventsoluble, and said solvent insoluble elements are thin metal film circuitand thermosetting resin film, formed on said board.

It is desirable that a fire retardant containing no halogen element isadded to said solvent soluble thermoplastic resin element.

Further, the present invention also provides a method for manufacturinga recycled resin mold comprising dissolving discarded compound resinmolds in solvent to separate solvent insoluble element(s), recoveringsaid thermoplastic resin element(s) dissolved in said solvent byevaporating said solvent, and recycling said recovered thermoplasticresin as resin mold material. In said method for manufacturing arecycled compound resin mold, it is desirable recycle aid agent(s) is(are) added to said recycled thermoplastic resin recovered byevaporating said solvent in which said thermoplastic resin is dissolved,and it is desirable said recycle aid agent(s) is(are) virginthermoplastic resin and/or virgin thermoplastic resin havingcompatibility with said recycled thermoplastic resin and/or rubber-likematerial and/or inorganic reinforcing material and/or organicreinforcing material.

Since said compound resin mold consists of thermoplastic resinelement(s) (soluble thermoplastic resin element) being solvent solubleand having a heat distortion point higher than 80° C., said point beingmeasured by the method following ASTM D648 and applying a load 1,820MPa, and element being solvent insoluble (insoluble element), saidsoluble thermoplastic resin element(s) has(have) enough mechanicalstrength(s) to be used for the printed circuit board, and whendiscarded, said compound resin mold is recycled, after which saidsoluble thermoplastic resin element(s) and said insoluble element(s) aresimply separated by dissolving said discarded compound resin mold insolvent, since said insoluble element(s) do not dissolve therein. Saidseparated thermoplastic resin(s) is recycled as resin mold material(s)and usable insoluble element(s) being separated and recovered by theproper method.

PREFERRED EMBODIMENT

The present invention is detailed below.

[Soluble Thermoplastic Resin]

The thermoplastic resins used in said compound resin mold of saidprinted circuit board and the like of the present invention is such asstyrene group resin, vinyl acetate group resin, methacryl group resin,vinyl group resin, amino group resin, olefin group resin, ester groupresin, ether group resin and the like, such as ethylene-vinyl acetateresin, polystyrene, high impact polystyrene(HIPS), styrene-acrylonitrileresin, styrene-acrylontrile-butadiene resin(ABS), polyvinyl acetate,polymethyl methacrylate, thermoplastic polyester, thermoplasticpolyamide and the like.

In particular, in a case where said compound resin mold is a printedcircuit board, it is desirable that soluble thermoplastic resin having aheat distortion point higher than 8° C., said point being measured bythe method following ASTM D648, is used, and said thermoplastic resin issuch as polycarbonate(PC), polyetherimide(PEI), polyamideimide(PAI),polysulfone(PSF), polyamide(PA), polyethylene terephthalate(PET),polybutylene telephtalate(PBT), polyethylene naphthalate(PEN),polyarylate(PAR), polyphemylane ether(PPE), modified polyphenyleneether(m-PPE) and the like.

Further, the thermoplastic resin used in the present invention is astyrene group thermoplastic elastomer such as styrene-butadiene blockcopolymer (SBS), styrene-isoprene-styrene block copolymer(SIS),styrene-ethylene-butylene-styrene block copolymer(SEBS),styrene-ethylene-propylene-styrene block copolymer(SEPS) and the like.Said thermoplastic elastomer is used as the main material of said resinmold, and further, said thermoplastic elastomer may be mixed with otherthermoplastic resins as described above, or said thermoplastic elastomermay be used as a material for the attachment to said resin mold.

Further, since said thermoplastic resin used in the present invention isdissolved in solvent when said thermoplastic resin is recycled, it isdesirable that said themoplastic resin is chemically stable for solvent.

[Insoluble Element]

The insoluble element used in the present invention is one such as ametal, ceramic, wood material, thermosetting resin, filler and the like,which are attached to said soluble thermoplastic resin element. Forexample, in the case of a printed circuit board, said insoluble elementis such as thin metal film circuit formed on the surface of saidthermoplastic resin board, said metal being Cu, solder used for theconnection of said circuit, said solder including thermosetting resin,ultraviolet cure type resin and the like in which electroconductingfiller such as metal powder and the like is dispersed, glass fiber andcellulose fiber mixed in said board, and inorganic filler. Further, inthe case of the electromagnetic interference shield resin mold, saidinsoluble element is such as metal powder, said metal being such assilver, copper, nickel, cobalt, iron, aluminum, and the like, carbonpowder, and the like which are mixed in said resin mold, carbon and saidmetal powder contained in the paint film on the surface of said resinmold, thermosetting resin in the paint and the like. Further, in ageneral resin mold, inorganic filler, organic filler and inorganicpigment are commonly added as insoluble elements. Said inorganic filleris such as a glass fiber, glass bead, carbon fiber, ceramic fiber, metalfiber, mica, talc, calcium carbonate, aluminum silicate, kaolin, silica,calcium metasilicate, bituminous material fine powder, zeolite,diatomaceous earth, silica sand, pumice powder, slate powder alumina,iron oxide, aluminum sulfate, barium sulfate, lithopone, calciumsulfate, magnesium oxide, molybdenum disulfide, and the like, andorganic filler is such as a rubber powder, ebonite powder, shellac, woodpowder, coconut powder, cork powder, cellulose powder, wood pulp, paper,cloth, silicone resin fine powder, and the like, and further, inorganicfiller is such as a mica powder, graphite, glass ball(GB), volcanicglass balloon, carbon balloon, anthracite powder, artificial crystalstone, silica spherical fine powder and the like, and said inorganicpigment is such as a titanium oxide, carbon block, Indian red, chromeyellow and the like.

Furthermore, said insoluble element includes the thermosetting resinused to connect each respective resin mold, and to connect a resin moldwith non-resin parts, and thermosetting resin and inorganic pigmentcontained in the paint used for the coating of a resin mold.

Said thermosetting resin is such as a melamine resin, alcohol modifiedmelamine resin, phenolic resin, urea resin, resorcinol resin,benzoguanamine resin, epoxy resin, thermosetting urethane resin,thermosetting acrylic resin, melamine-alkyd resin and the like, and saidpigment is such as a titan oxide, carbon black, Indian red, chromeyellow and the like.

Further, resist film is formed by coating or printing in the printingink is applied on the surface of said printed circuit board. The resinused in coating agent for resist, paint or ink is such as shellac,rosin, ester gum, hardened rosin, decolorized shellac, alkyd resin,rosin modified alkyd resin, phenol modified alkyd resin, epoxy modifiedalkyd resin, styrenated alkyd resin, acrylated alkyd resin, urethanemodified alkyd resin, silicon modified alkyd resin, amino modified alkydresin, phthalic resin, amino resin, melamine resin, butyl melamineresin, methyl melamine resin, benzoguanamine resin, amino alkydcopolycondensation polymer, urea resin, epoxy resin such as glycidylether type (bisphenol A type, bisphenol F type, 2,6-xylenol type,brominated bisphenol A type, phenol novolak type, o-cresol novolaktype), glycidyl ester type, glycidyl amine type (aromatic amine),alicyclic type and the like, polyurethane resin; one-componentpolyurethane resin such as oil modified polyurethane resin, moisturehardening type polyurethane resin, heat cross linking typepolyurethane(block isocyanate), lacquer type polyurethane and the like;catalyst hardened poly urethane resin; two-component polyurethane resin,such as polyol setting type polyurethane, acryl polyol, polyesterpolyol, polyetherpolyol, epoxy polyol, isocyanate, polyol and the like;unsaturated polyester resin, phenol resin, NAD resin, emulsion typeresin such as acryl resin emulsion, styrene acryl resin emulsion, epoxyresin emulsion, urethane resin emulsion, acryl silicon resin emulsion,epoxy resin emulsion, urethane resin emulsion, acryl silicon resinemulsion, fluororesin emulsion; water soluble resin such as watersoluble alkyd resin, water soluble acrylated alkyd resin, water solublepolyester resin, water soluble acryl resin, water soluble epoxy esterresin, water soluble melamine resin; chlorinated polyolefin resin (e.g.chlorinated PE, chlorinated PP and the like), chlorinated rubber,silicone resin; modified resin such as alkyd resin, epoxy resin,polyester resin, acryl resin, urethane resin, fluororesin, xylene resin,phenol-xylene resin, oil petroleum resin, ketone resin, rosin modifiedmaleic resin, cumarone resin, ethyl silicate, ultraviolet curingresin(e.g. unsaturated polyester, urethane acrylate, epoxy acrylate,ester acrylate ), vinyl chloride, vinyl acetate, vinyl acetate-vinylpropionate resin, vinylidene chloride, maleic acid, polyvinyl alcohol,polyvinyl butyral (including epoxy resin, phenol resin, melamine resin,urea resin, thermostatic resin having a functional group reacting crosslinking which can react with isocyanate ), acrylic resin such asthermoplastic acrylic resin, thermosetting acrylic resin, epoxy settingacrylic resin, melamine modified resin, acrylpolyol for cross-linkingagent of block isocyanate, modified acrylic resin, vinyl acetatemodified resin, styrene modified resin, vinyl toluene acryl siliconeresin, polyamide and the like.

Only the solvent insoluble resin described above are usable in thepresent invention, and said resin is cured by using isocyanate forcross-linking, said thermoplastic resin becoming insoluble.

[Fire Retardant]

For example, in said printed circuit board, a fire retardant is added toprevent any igniting due to overheated drums.

Up to now, a fire retardant containing chlorine or bromine has been usedbut said fire retardant containing halogen, on incineration, remarkablycontaminates the atmosphere. Accordingly, a non-halogen type fireretardant is desirable for use in said compound resin mold of thepresent invention. Said no halogen fire retardant is such as diantimonytrioxide, antimony type fire retardant, diantimony pentaoxide, sodiumantimonite, magnesium hydroxide, aluminum hydroxide, zinc borate,guanidine type fire retardant, guanidine sulfamate, guanidine phosphate,guanyl urea phosphate, zirconium type fire retardant, tin compound,molybdenum compound, red phosphorus, guanidine type fire retardant,silicon type fire retardant, phosphate type fire retardant such asphosphate, phosphorous compound, tris allyl phosphate,tris(3-hydroxypropyl) phosphine oxide, tris(tribromoneopentyl)phosphate, dimethyl methyl phosphate, aromatic condensed phosphate,ethylene ·bis ·tris(2-cyanoethyl) phosphorus bromide, ammoniumpolyphosphate, butyl pyrophosphate, butyl acid phosphate, butoxy ethylacid phosphate, 2-ethyl hexyl acid phosphate, melamine phosphate; fireretardant on the market such as fire retardants made by Sandoz ltd.,such as Sand flam 5060 which is organic phosphate fire retardant, fireretardants made by Nippon Chemical Industrial Co., Ltd. such asHishiguard RP, Hishiguard CP, Hishiguard Safe PM-24, Hishiguard SafePM-24I, Hishiguard Safe PM-34, Hishiguard Safe PM-341, Hishiguard SafePM-13, Hishiguard EP-15, Hishiguard UR-15, fire retardants made byRINKAGAKU KOUGYO CO., LTD. such as NOVA RED #120, NOVA RED #280, NOVAQUELL ST-100, NOVA QUELL ST-200, NOVAQUELL W-100, fire retardants madeby Albright & Willson such as AMGARD CRP, AMGARD CRPA, AMGARD MC, AMGARDPI, fire retardants made by Hoechst such as NG, NN, NF, NFF which arestabilization type fire retardants, SG, SN, SF, SFF which areunstabilization type fire retardants, reactive fire retardants such aschlorendic anhydride, diethoxy-bis-(2-hydroxyethyl)-aminomethyl·phosphate, phenyl phosphonic acid, phenyl phosphonic acid dichloride,diethylphenyl phosphonate, dimethyl phenyl phosphonate, diallylchlorendate, reactive noncombustible polyol,dibutylbis(2-hydroxypropyl)pyrophosphate, noncombustible stabilizersmade by ASAHI DENKA CO., LTD. such as ADECA SIZER ER-13, ADECA STABZS-66, ADECA STAB ZS-506 which are epoxy type stabilizers, stabilizersfor ABS type polymer blend such as butyl·tin·malate type,octyl·tin·malate type, butyl·tin sulfur type, stabilizers made by SANKYOYUKI GOSEI, such as Stan BM(N), Stan OMF, JF-9B, Stan JF-95B, StanBK-1100, Stan JF-95B, Stan BK-1100, Stan ONZ-20, Stan ONZ-22, StanONZ-22P and the like, stabilizers made by Kyowa Chemical Industry Co.,Ltd. such as DHT-4A-2 and the like, silicon resin, silicon oil,fluororesin, fluoro type oil, noncombustible stabilizers made by ADECAARGUS such as Mark EP-13, EP-17, EP-22, Mark273 which are epoxy typestabilizers, other noncombustible stabilizers made by ADECA ARGUS suchas Mark-ZS-66, ZS-506, stabilizers for ABS-PVC type polymer blend madeby SANKYO YUKI GOSEI, such as StanMMS, MC and the like.

[Solvent]

A discarded compound resin mold of the present invention is dissolved insolvent when it is to be recycled. Said solvent used for dissolving saiddiscarded compound resin mold, in other words, the thermoplastic resinof said resin mold, is such as n-heptane, n-hexane, gasoline forindustrial use, kerosene, toluene, xylene, benzene, trimethylbenzene,tetralin, dipentene, turpentine, cyclohexane, methylcyclohexane,ethylcyclohexane, styrene and the like; alcohol such as methanol,ethanol, modified alcohol, n-propanol, iso-propanol, n-butanol,iso-butanol, sec-butanol, tert-butaol, n-amyl alcohol, iso-amyl alcohol,2-ethylhexanol, methylisobutylcarbinol, benzyl alcohol, furfurylalcohol, ether alcohol, ether; methyl cellosolve, butyl cellosolve,isobutyl cellosolve, tert-butyl cellosolve, isopropyl cellosolve, hexylcellosolve, methoxy butanol, 3-methyl-3-methoxybutanol, carbitol, methylcarbitol, butyl carbitol, propylene glycol mono methyl ether,dipropylene glycol mono methyl ether, dioxane and the like; ester,ether, methyl acetate, ethyl acetate, n-propyl acetate, isopropylacetate, isobutyl acetate, iso amyl acetate, methyl cellosolve acetate,cellosolve acetate, butyl cellosolve acetate, methoxy propyl acetate,methoxy butyl acetate, carbitol acetate, butyl carbitol acetate,3-methyl 3-methoxybutanol acetate, 3-ethoxyetanol propionate, ketone,acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone,methyl hexyl ketone, methyl amyl ketone, cyclohexanone(anone), diacetonealcohol, isophorone, methylene dichloride, ethylene tetrachloride,1,1,1-trichloroethane, o-dichlorobenzene, CFC, HCFC, tetrahydro furan,2-nitro propane, N,N-dimethylformamide and the like. Said solvent issingly used or a mixture of two or more solvents is used.

Said solvent used in the present invention should have a high solubilityfor said thermoplastic resin, and chemical stability for saidthermoplastic resin, and further, said solvent desirably has a lowtoxicity and a low boiling point(such as lower than 150° C.). In thepresent invention, said solvent is selected considering saidrequirements for thermoplastic resin to be dissolved.

[Dissolving process]

Said discarded compound resin mold made of said soluble thermoplasticresin is dissolved in solvent as is or after said discarded resin moldis crushed. To promote the solubility of said discarded resin mold insaid solvent, said solvent or solution may be stirred and/or heated to adegree, meaning that said stirring and/or heating does not damage theproperties of said recycled thermoplastic resin. An airtight tank isdesirable for dissolving process, and if necessary, said dissolving iscarried out in an inert atmosphere such as a nitrogen gas atmosphere,and further, said tank may also be vibrated, as opposed to stirring.

[Insoluble Element Removing Process]

Said discarded resin mold dissolved in solvent in the above describeddissolving process is separated into a soluble thermoplastic resinelement and an insoluble element.

For this separation, for example, a centrifuge and/or filtration processis applicable.

[Resin Recovering Process]

Said insoluble element(s) is(are) removed from said solution in saidinsoluble element removing process and said solvent is removed from saidsolution by evaporation through heat. Vacuum distillation may bedesirable in this process. The thermoplastic resin recovered asdescribed above is used as is for molding material, or after crushing orpelletizing.

The resultant molding material is desirably molded as is to be a newresin mold from the point of recycling, but if necessary, virgin resinmaterial may be mixed in with said molding material, or a recycle aidagent as described later, is mixed in with said molding material toimprove impact resistance of said molding material before said moldingmaterial is manufactured into said resin mold.

The solvent recovered in said resin recovering process is reusable assolvent, and metal, inorganic filler, and the like, once removed asinsoluble elements, are recovered as much as possible, and recycled.

[Recycle Aid Agent]

Said recycle aid agent used in the present invention is such as a virginthermoplastic resin of the same kind as the thermoplastic resin of saidresin mold, or virgin thermoplastic resin having compatibility with thethermoplastic resin of said resin mold or rubber like material. Saidvirgin thermoplastic resin and said rubber like material may be usedtogether as recycle aid agents.

Said rubber like material is a graft rubber wherein the trunk part isdiene group rubber, olefin group rubber or acrylic rubber and the branchpart is a graft chain having compatibility with the thermoplastic resinof said resin mold so that said rubber like materials as said recycleaid agents used in the present invention are diene group rubber graftpolymer, olefin group rubber graft polymer, and acrylic rubber graftpolymer. Graft copolymers of olefin group rubber and graft copolymer ofacrylic rubber are preferable graft copolymers as said recycle aidagents since said graft copolymers have respectably good heatstabilities.

Each rubber like material is illustrated below.

A: Olefin Group Rubber Graft-polymer

Said olefin group rubber used in said equal quality recycle aid agent ofthe present invention is polymer or copolymer of one or more kind(s) ofan α-olefin or copolymer of one or more kind(s) of said α-olefin and oneor more kind (s) of other monomer(s)

which can be copolymerized with said α-olefin(s). Typically, said olefingroup rubber may be copolymer of ethylene and one or more kind(s) ofother α-olefin(s) or copolymer of ethylene and one or more kind(s) ofother α-olefin(s) and other monomer(s) which can be copolymerized withsaid α-olefin, especially said other monomer is non-conjugated dienecompound.

In said ethylene-α-olefin group copolymer, α-olefin which iscopolymerized with ethylene may be α-olefin having 3 to 12 carbon atomssuch as propylene, butene-1, 4-methyl pentene-1, hexane-1, Octene-1, andthe like.

Said non-conjugated diene compound may be such as dicyclopentadiene,tricyclopentadiene, 5-methyl-2,5-norbornadiene,5-methylene-2-norbornene, 5-vinyl-2-norbornene,5-ethylidene-2-norbornene, 5-isopropylidene-2-norbornene,5-isopropenyl-2-norbornene, 5-(1-butenyl)-2-norbornene,5-(2-propenyl)-2-norbornene, 5-(5-hexenyl)-2-norbornene,4,7,8,9-tetrahydro-indene, isopropylidenetetrahydro-indene,cyclooctadiene, vinylcyclohexene, 1,5,9-cyclododecatoluene,6-methyl-4,7,8,9-tetrahydroindene, 2,2′-dicyclopentenyl,trans-1,2-divinylcyclobutane, 1,4-hexadiene, 2-methyl-1, 4-hexadien,1,6-actadien, 1,7-octadien, 1,8-nonadiene, 1,9-decadiene,3,6-dimethyl-1,7-octadiene, 4,5-dinethyl-1,7-octadiene,1,4,7-octatriene, 5-methyl-1,8-nonadiene and the like.

Preferably said non-conjugated diene compound may be5-ethylilidine-2-norbornen(ENB) and/or dicyclopentadiene (DCP), morepreferably, dicyclopentadiene. An mixture of an olefin group rubbergraft polymer containing 5-ethylidene-2-norbornen and an AS or a PSgives a resin mold having a good appearance.

Further, in the case of said olefin group rubber graft polymercontaining EPDM, impact strength of the resulting resin mold may begreater than in the case of said olefin group rubber graft polymercontaining EPM.

The molar ratio of ethylene-α-olefin and a non-conjugated dienecompound, if necessary, in said olefin group rubber graft polymerethylene/α-olefin/non-conjugated diene compound is preferably0.2˜1.0/0.2˜0.8/0˜0.2 and more preferably 0.5˜0.9/0.25˜0.75/0˜0.1 andmolar ratio of ethylene/propylene is 60/40 and over, preferably 65/35and over and from a standpoint of recyclability of mechanicalproperties( impact resistance and the like) of the resulting resin mold,ethylene-propylene copolymer rubber(EPM) or ethylene-propylene-nonconjugated diene compound terpolymer (EPDM) in which ethylene is richlycontained is preferably used.

Further, the mooney viscosity (ML₁₊₄, 100° C.) of said ethylene-α-olefingroup copolymer is preferably 5 to 150, more preferably 10 to 120, theoptimum viscosity is 20 to 80 over and from a stand point ofrecyclability.

Typical olefin group rubber may be ethylene-propylene copolymer rubber(EPM), ethylene-propylene-non-conjugated diene compound terpolymer(EPDM), ethylene-butene copolymer rubber (EBM),ethylene-butene-non-conjugated diene compound terpolymer(EBDM). The samenon-conjugated diene compound as used in EPDM may be used in EBDM.

To give compatibility with the objective thermoplastic resin to saidolefin group rubber, styrene group monomer and/or nitrile group monomeris (are) graft-copolymerized to said olefin group rubber.

Said styrene group monomer being graft-copolymerized to said olefingroup rubber may be such as one or more kinds of styrene monomerscomprising styrene, α-alkylmonovinylidene aromatic monomer (e.g.α-methylstyrene, α-ethylstyrene, α-methylvinyltoluene,α-methyldialkylstyrene and the like), cyclo-substituted alkylstyrene(e.g. o, m, or p-vinyltoluene, o-ethylstyrene, p-ethylstyrene,2,4-dimethylstyrene, p-tert butylstyrene and the like),cyclo-substituted halo styrene (e.g. o-chlorostyrene, p-chlorostyrene,o-bromostyrene, 2,4-dichlorostyrene and the like), cyclo-alkyl, cyclohalo substituted styrene (e.g. 2-chloro-4-methylstyrene,2,6-dichlorostyrene and the like), vinyl naphthalene, vinyl anthraceneand the like.

In general, alkyl group having 1 to 4 carbon atom(s) includes both linerchain and branched chain.

Said nitrile group monomer being graft-copolymerized to said olefingroup rubber may be such as acrylonitrile, methacrylonitrile,ethacrynitrile, fumaronitrile, a mixture of two or more kinds of saidnitrile, and the like.

Besides said styrene group monomer and said nitrile group monomer, othermonomer (third monomer) may be copolymerized. Any kind of monomer whichcan be copolymerized with said styrene group monomer and nitrile groupmonomer may be used for copolymerization and generally said thirdmonomer may be such as (meth)acrylates such as methyl(meth)acrylate,ethyl(meth)acrylate and the like, maleimides such as N-phenylmaleimide,maleimide, N-methylmaleimide, N-ethylmaleimide, (p-bromophenyl)maleimidemethacrylate, cyclohexylmaleimide and the like, unsaturatednitrile compounds such as maleic anhydride methacrylonitrile and thelike.

Alkyl ester having 1 to 4 carbon atoms, especially methacrylate ispreferable as (meth)acrylate.

To graft-polymerize said monomer(s) to said olefin rubber,polymerization system in which said monomer(s) is(are) polymerized byoil soluble or water soluble initiator and/or high energy ray such asultraviolet ray, electron beam, and the like under existence of saidolefin group rubber is applied. In said polymerization system, generalpolymerization method such as bulk polymerization, suspensionpolymerization, solution polymerization, emulsion polymerization and thelike is applied.

Said graft olefin group rubber produced by said graft polymerizationincludes both graft polymer in the narrow sense consisting of olefingroup rubber as a trunk and a polymer chain of said monomer(s) as abranch and mixture of said graft polymer in the narrow sense and olefingroup rubber and/or polymer of said monomer(s).

Said olefin group rubber graft polymer used as said recycle aid agentand suitable for each of said thermoplastic resin is described below.

(1) Graft Polymer for Styrene Group Resin

One or more kind(s) of styrene or styrene analog monomer(s) graftpolymerized olefin group rubber (styrene graft olefin group graftpolymer) is used for the styrene group resin especially PS or HIPS. Saidstyrene graft olefin group graft polymer has the polymer branch chain ofsaid styrene group monomer having substantially the same solubilityparameter as said styrene group resin, especially PS, so that saidstyrene graft olefin group graft polymer has good compatibility with PS.

For styrene group resin, especially AS or ABS, olefin group rubber graftpolymer wherein one or more kind(s) of styrene and/or other styrenegroup monomer(s) and one or more kind(s) of acrylonitrile and/or othernitrile group monomer(s) are graft polymerized to said olefin grouprubber (styrene-nitrile graft olefin graft polymer) is used as saidrecycle agent.

Other monomer(s) which can be copolymerized with said styrene groupmonomer(s) and said nitrile group monomer(s) may be copolymerized withsaid styrene group monomer(s) and said nitrile group monomer(s).

Said styrene-nitrile graft olefin group graft polymer has thestyrene-nitrile copolymer branch chain having substantially the samesolubility parameter as As or ABS, so that said styrene-nitrile graftolefin group graft polymer has a good compatibility with AS or ABS.

In said olefin group rubber graft polymer, said olefin group rubber mayused singly or a mixture of two or more olefin group rubber may be usedas said olefin group rubber. In said olefin group rubber graft polymer,the content of said olefin group rubber is generally 10 to 80% byweight, preferably 15 to 75% by weight, the content of monomer(s)grafted (graft ratio) is generally 90 to 20% by weight, preferably 55 to25% by weight, and in the case of styrene-nitrile graft olefin grouprubber graft polymer, the content of styrene group monomer is preferably5 to 95% by weight and the content of nitrile group monomer ispreferably 95 to 5% by weight. In the range described above, improvementeffect on the compatibility of said olefin group rubber graft polymerwith said thermoplastic resin, on the recyclability of saidthermoplastic resin, in other words, degradation preventing effect onimpact strength of said thermoplastic resin can be balanced when saidthermoplastic resin is recycled.

Since said olefin group graft polymer is mixed into said thermoplasticresin on a moleculer level, the size of said olefin group graft polymerparticles are desirably less than 5.0 μm, more desirably in the range of0.001 to 2.0 μm. In this particle size range, the improvement effect onthe recyclability of said olefin group rubber graft polymer may beespecially remarkable.

In a case where two or more identical or different kinds of said olefingroup rubber having respective different particle sizes are used incombination, the amount of olefin group rubber graft polymer added tothermoplastic resin can be reduced, as said thermoplastic resin'sphysical properties are improved.

Further, the reduced viscosity of toluene soluble component of saidolefin group rubber graft polymer η sp/c (0.5 g/dl toluene solution at30° C.) is preferably in the range of 0.30 to 1.00 g/dl, and morepreferably in the range of 0.50 to 0.80 g/dl.

Concretely, said olefin group rubber graft polymer may be styrene graftEPM and/or EPDM (St-g-EPM, St-g-EPDM, St-g-EPM-EPDM) which are thatstyrene is graft-polymerized with EPM and/or EPDM in the case of usingfor PS or HIPS, acrylonitrile-styrene graft EPM and/or EPDM (AnSt-g-EPM,AnSt-g-EPDM, AnSt-g-EPM-EPDM) which are that acrylonitorile and styreneare graft-polymerized with EPM and/or EPDM in the case of using for ASor ABS, styrene graft EBM and/or EBDM (St-g-EBM, St-g-EBDM,St-g-EBM-EBDM) which are that styrene is graft-polymerized withethylene-butene rubber (EBM) and/or ethylene-butene-diene terpolymer(EBDM) in the case of using for PS, acrylonitrile-styrene graft EBMand/or EBDM (AnSt-g-EBM, AnSt-g-EBDM, AnSt-g-EBM-EBDM) which are thatAcrylonitrile and styrene are graft-polymerized with EBM and/or EBDM inthe case of using for AS or ABS.

In this invention, AS and AnSt-g-EPM mixed resin is described as EPM-AS,AS and AnSt-g-EPDM mixed resin is described as EPDM-AS, AS, AnSt-g-EPMand AnSt-g-EPDM mixed resin is described as EPM-EPDM-AS, PS and St-g-EPMmixed resin is described as EPM-PS, PS and St-g-EPDM mixed resin isdescribed as EPDM-PS, and, PS, St-g-EPM and St-g-EPDM mixed resin isdescribed as EPM-EPDM-PS.

Further, mixed resin of graft rubber wherein nitrile monomer such asacrylonitrile and styrene group monomer are graft copolymerized to saidacrylic rubber and AS is described as acryl-AS and mixed resin ofstyrene group monomer grafted acrylic rubber and AS is also described asacryl-PS.

(2) Graft Polymer for PPE Group Resin

PPE consists of structure unit having phenyl group as described above,so that styrene graft olefin group rubber graft polymer such asSt-g-EPM, St-g-EPDM, St-g-EPM-EPDM, St-g-EBM St-g-EBDM, St-g-EBM-EBDMand the like are preferably selected. Said olefin group rubber graftpolymer has styrene. polymer side chain having similar solubilityparameter to PPE so that said olefin group rubber graft polymer has goodcompatibility with PPE group resin and said olefin group rubber graftpolymer is mixed stably in said PPE group resin without separation toimprove the recyclability of said PPE group resin.

In this invention, PPE and St-g-EPM (which is olefin type rubber graftpolymer) mixed resin is described as EPM-PPE, PPE and St-g-EPDM mixedresin is described EPDM-PPE, PPE, St-g-EPM and St-g-EPDM mixed resin isdescribed as EPM-EPDM-PPE, PS and EPM-PPE mixed resin is described asEPM-PS-PPE, PS and EPDM-PPE mixed resin is described as EPDM-PS-PPE,and, PS, St-g-EPDM and St-g-EPDM mixed resin is describedEPM-EPDM-PS-PPE.

Furthe, mixed resin of PPE and acrylic rubber graft polymer,St-g-acrylic rubber is as described acryl-PPE, mixed resin of PS andacryl-PPE is also described as acryl-PS-PPE.

B: Acrylic Rubber Graft Polymer

Said acrylic rubber used in the present invention may be such asacrylate homopolymer having alkyl group having 2 to 8 carbon atomspreferably, such as ethylacrylate, n-butylacrylate, 2-ethylhexylacrylateand the like, copolymer comprising two kinds and over of acrylatemonomers mentioned above, copolymer comprising one or more kinds ofacrylate monomer(s) mentioned above and butadiene or one or more kindsof other monomer(s) such as non-conjugated diene compounds which can beused for EPDM similarly, acrylonitrile, methylmethacrylate, vinylacetate, styrene, ethylene, propylene and the like, copolymer comprisingone or more kinds of acrylate monomer(s) and functional monomer(s) suchas acrylic acid methacrylic acid, β-hydroxyethylmethacrylate,acrylamide, dimethylaminoethylmethacrylate and the like, orpolymerization silane coupling agent(s) such asγ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane,p-trimethoxysilylstyrene, p-triethoxysilylstyrene, p-trimethoxysilyl,α-methylstyrene, p-triethoxysilyl-α-methylstyrene,γ-acryloxypropyltrimethoxysilane, vinyltrimethoxysilane,N-β(N-vinylbenzylaminoethyl-γ-aminopropyl) trimethoxysilanehydrochloride and the like.

As acrylic rubber for common use, copolymers, copolymerized with abovementioned functional monomer, such as polyethyl acrylate, poly n-butylacrylate, n-butyl acrylate-acrylonitrile copolymer,n-butylacrylate-butadiene copolymer, n-butyl acrylate-ethylenecopolymer, n-butyl acrylate-γ-methacryloxypropyltrimethoxysilanecopolymer, n-butylacrylate-vinyltrimethoxysilane copolymer and the likemay be used in this invention.

Noramal-Butyl acrylate-butadiene copolymer having a mole ratio ofn-butylacrylate/butadiene 30/70 and over is preferable to acrylicrubber.

Said acrylic rubber may be produced by suspension polymerization,emulsion polymerization, and the like.

Styrene group monomer(s) or styrene group monomer(s) and nitrile groupmonomer(s) are graft polymerized to said acrylic rubber to give saidacrylic rubber compatibility with styrene group resin, PPE group resinand PC group resin the same as with said olefin group rubber. To balancecompatibility and degradation preventive effectiveness of impactstrength in recycling, the content of said acrylic rubber may bepreferably 10 to 80% by weight, more preferably 15 to 75% by weight andthe content of said grafted monomer(s) (graft ratio) may be preferably90˜20% by weight, more preferably 55 to 25% by weight in all. In thecase of styrene-nitrile graft acrylic rubber graft polymer, the contentof styrene group monomer(s) may be preferably 5 to 95% by weight and thecontent of nitrile group monomer(s) may be preferably 95 to 5% byweight.

In above described range, compatibility of said acrylic rubber graftpolymer with said thermoplastic resin and recyclability of saidthermoplastic resin, in other words, degradation preventiveeffectiveness of impact strength balance respectively.

In the present invention, if desired, an inorganic reinforcement such asa calcium carbonate, magnesium carbonate, barium sulfate, calciumsulfate, calcium sulfite, calcium phosphate, calcium hydroxide,magnesium hydroxide, aluminum hydroxide, magnesium oxide, titaniumoxide, iron oxide, zinc oxide, alumina, silica, diatomite, gypsum, talc,clay, asbestos, mica, glass fiber, carbon fiber, calcium silicate,bentonite, white carbon, carbon black, iron powder, aluminum powder,powdered feldspar, slag, fly ash, cement, zirconia powder, and the like,an organic reinforcement such as a polyamide fiber, Kevlar fiber, aramidfiber, polyester fiber, acryl fiber, viscose fiber, acetate fiber,paper, and the like may be used as a recycle aid agent. Said reinforcingmaterial may be used singly or two or more kinds of said reinforcingmaterials may be used together.

The present invention is illustrated by following EXAMPLES, however saidEXAMPLES do not limit the scope of the present invention.

EXAMPLE 1

(Molding)

ABS resin (soluble thermoplastic resin element) containing 40% by weightof glass fiber (insoluble element) and a styrene modified PPE (solublethermoplastic resin element) containing 40% by weight of glass fiber anda fire retardant containing phosphorus were used as mold materials. Bothkinds of said mold materials were injection-molded respectively using aninjection molding machine, its clamping pressure settled to be 100 tonsto manufacture printed circuit board (Print Wire Board PWB) base molds.

In said injection molding, to prevent separation of the glass fiber ineach resin, the temperature of said mold surface was settled to behigher than each resin's glass transition temperature(Tg) using a highfrequency induction heating apparatus. Besides heating by high frequencyinduction, heating by a halogen lamp, heating by steam, heating byheater, oil, and the like can be applied to heat the inside of the mold.Further, a polycarbonate (soluble thermoplastic resin element)containing 40% by weight of glass fiber (insoluble element) was used asa mold material and said mold material was molded using the same methodas described above to manufacture a PWB base mold.

The three kinds of PWB base molds, manufactured as described above,exhibited no glass fiber separation on visual inspection, demonstratingthat plating and coating layer's adhesive strength suffers nodeterioration as a result of said glass fiber separation.

[Circuit Forming ]

Three kinds of said PWB base molds were treated respectively with amixed solution consisting of a mixture of chromic acid anhydride,potassium dichromate and sulfuric acid for etching, then washed withwater, after which a their catalyst was attached to each respective PWBbase mold.

Next, each respective PWB base mold was first coated with a chemicalcopper plating, then an electric copper plating to form a thin copperfilm on the surface of each respective PWB base mold.

An ultraviolet curing type paint containing an epoxy acrylate resin asmain component was then coated on the surface of said thin copper filmof said PWB base mold by pad printing, after which said coating film wastreated with irradiated ultra violet rays, curing said coating film ofsaid ultraviolet curing type paint, making it an insoluble element. Theuncured part(s) of said coating film was(were) removed with solventafter which said PWB base mold was nitric acid treated by etching, theremaining part(s) of said coating film to form a circuit.

(Manufacture of PWB)

An epoxy resin paint(insoluble element) was coated on the surface ofeach PWB on which said circuit was formed, to protect said thin copperfilm of said circuit. Further, letters and the like were printed on saidepoxy resin paint's coating film with a printing ink containing epoxyresin as its main component, and a ┌Repelle(Ri-pe-re)┘ symbol wasprinted on the surface of each PWB, to indicate recyclability. IC(s),resistance(s), and the like were assembled into each PWB.

(Soldering)

Said IC(s), resistance(s), and the like were assembled into each PWB byflowing each PWB for three seconds in a solder A consisting of Sn-58 Bi(which has a melting point of about 140° C.), a solder B consisting ofSn-73Pb(with a melting point about 180° C.), and a solder C consistingof Sn-3.0 Ag-0.5Cu (with melting point of about 220° C.), each beingsoldered to the copper plated circuit part during the PWB's assembly(PWBA).

(Recycling of PWBA)

As described above, there were three respective kinds of PWB base mold;these consisted of ABS, a modified PPE, and polycarbonate, eachrespective PWB containing 40% by weight of glass fiber, with thin copperfilm circuits formed on the surface of each respective PWB, further,IC(s), resistances, and the like were added to said circuit, to completethe Print Board Assembly(PWBA).

To recycle said discarded PWBA, said PWBA was dipped in aMEK/chloroform(50/50) solvent mixture or a toluene solvent withoutremoving the IC(s), resistance(s), and the like assembled into said PWB,and without crushing said PWBA, and if necessary said PWBA having beendipped in said solvent was heated at about 60° C. to dissolve saidsoluble thermoplastic resin element. The resulting solution of saiddiscarded PWBA was separated using a centrifugal separator, and thenfiltered to remove the insoluble elements such as Cu thin film, inkfilm, and the like from said PWBA after which said solvent(s) of saidsolution of said thermoplastic resin was(were) distilled to recover saidthermoplastic resin.

The recovered thermoplastic resin lumps (ABS, styrene modified PPE, orPC) were crushed respectively, and 40% by weight of glass fiber wasmixed in each said recovered crushed thermoplastic resin. Then 400 partsby weight of virgin ABS or styrene modified PPE or PC, each of whichcontains 40% by weight of glass fiber, were mixed into 100 parts byweight of each mixture of said recovered crushed thermoplastic resin andglass fiber, and the resulting mixtures were respectively pelletized toprepare the mold material for recycled printed circuit board.

(Remold)

Using said recycled mold materials, recycled printed circuit board A wasmanufactured by injection molding in the same way as described above.

The Izod impact strength(kg-cm/cm) of each of the recycled printedcircuit board A was measured by the method following ASTM-D256. Tocompare with Izod impact strength of said recycled printed circuit boardA, printed circuit board X(s), made of virgin ABS containing 40% byweight of glass fiber, virgin modified PPE containing 40% by weight ofglass fiber, and virgin PC containing 40% by weight of 40% glass fiber,were manufactured by injection molding, and the Izod impact strength ofeach printed circuit board X was also measured. The results are shown inTable 1. TABLE 1 Izod impact strength Resin Printed circuit board APrinted circuit board X ABS 6.5 6.4 Modified PPE 5.8 5.4 PC 21.5 20.0

The ratio of impact of impact strength(%) deterioration=(the Izod impactstrength of board A)/(the Izod impact strength of board X)×100, wascalculated for each resin, and calculated deterioration ratios of theIzod impact strengths(%) were 101%, 107%, and 107% respectively,confirming that each board A has enough mechanical strength for printedcircuit board.

EXAMPLES 2

A discarded ABS resin mold which was cabinet(front cover), was crushedwherein a paint consisting of nickel powder and carbon powder(acetyleneblack/carbon black) as conductive materials and styrene modified acrylicresin having compatibility with ABS resin as vehicle was coated on thesurface of said resin mold to form a conductive coating film.

Said crushed resin mold was dissolved in methyl ethyl ketone to recoverABS resin as in EXAMPLE 1.

The Izod impact strength (Kg-cm/cm) of said recovered recycled ABS resinwas measured by the method following ASTM-D256 method in the same manneras in EXAMPLE 1. Further, virgin ABS resin was molded and the heathistory's effect on the resulting mold was given, to provide the samecondition for heat degradation as said recycled resin, to the resin ofsaid resin mold, and a sample for comparison was prepared. The Izodimpact strength of said sample was also measured. The results are shownin Table 2. TABLE 2 EXAMPLE Recycled ABS resin Virgin ABS resin 2 16.816.7

The deterioration ratio of the Izod impact strength=(the Izod impactstrength of recycled resin)/(the Izod impact strength of virginresin)×100, was calculated the result being 100%, confirming that saidrecycled resin contained no insoluble contaminants, and was useful asthe resin material for such as a printer cabinet.

EXAMPLE 3

A discarded resin mold was crushed as is wherein thin nickel film wasformed on the surface of an ABS resin base mold to shield it fromelectromagnetic wave using a chemical nickel plating, and athermosetting acryl modified urethane resin paint was coated on saidthin nickel film for decoration, and further, logotype mark was printedon said paint coated layer using a two component ink containing athermosetting epoxy resin as its main component. Said crushed resin moldwas then dissolved in a solvent mixture of methyl ethylketone/toluene(60/40 weight ratio), and an insoluble element such assaid thin nickel film and the like, and a soluble thermoplastic resinelement, were then separated with a centrifugal separator. The resultingresin solution was then evaporated as in EXAMPLE 1 to recover the ABSlumps. It was confirmed that said ABS lumps contained no insolubleelements such as plating film, coating film, ink film and the like.

Said ABS lump was crushed and 5 parts by weight of recycle aid agentwhich was a graft rubbery polymer having compatibility with ABS wasadded to said crushed ABS lump to restore physical properties, whereinsaid graft rubbery polymer was an acrylonitrile-styrene graft EPDM,third components of said EPDM were DCP(molar ratio of E/P/DCP=65/25/10and Mooney viscosity ML₁₊₄ was 80 at 100° C., average particle size wasabout 1 μm, An/EPDM/st=about 23/29/48, and graft ratio was 71% byweight), and thus recycled mold material was prepared. The Izod impactstrength (Kg-cm/cm) was measured by the method following ASTM-D256 andthe result is shown in Table 3. TABLE 3 EXAMPLE Recycled ABS resinVirgin ABS resin 3 23.1 16.7

EXAMPLE 4

The electric nickel plating was coated on the surface of an ABS resinmold using said recycled mold material of EXAMPLE 3, and said platedresin mold was crushed and dissolved in the same manner as the formerEXAMPLES to separate insoluble element, and soluble element, and theresulting solution was evaporated to recover the resin, after which saidresin was crushed and pelletized to prepare recycled material. Themechanical properties of said recycled material were almost the same asthose of the recycled material of EXAMPLE 3. Further, it was confirmedthat said recycled material contained no plating film as an insolubleelement. The Izod impact strength (Kg-cm/cm) of said recycled materialwas measured by the method following ASTM-D256 and the result is shownin Table 4. TABLE 4 EXAMPLE Recycled ABS resin Virgin ABS resin 4 16.516.7

COMPARISON

The PWBA on the market was respectively dipped in MEK and then toluene,and kept for 48 hours at 3° C., wherein said PWBA has a base board madeof epoxy resin containing glass fiber, and IC and resistances areattached by soldering and then solubilities of base board, sealing agentof IC, printing ink, resist film and the like were estimated.

The results of FT-IR of MEK and toluene in which said PWBA wererespectively dipped and virgin MEK and virgin toluene were compared.

As a result, it was confirmed that the MEK and toluene in which saidPWBA were respectively dipped contained no exuding material.

Considering the results described above, it was expected that therecycling of the resin of said base board can be enforced by alternatingsolvent insoluble thermosetting resin with solvent soluble thermoplasticresin.

Further, it was confirmed following an energy dispersive X-rayspectroscopy (EDX) method, that the resulting solutions contained noinorganic material such as metal.

Industrial Utility

The thermoplastic resin contained in a discarded compound resin moldsuch as a printed circuit board and the like can be dissolved insolvent, so that a high temperature does not adversely affect saidthermoplastic resin during recovering, preventing the degradation ofsaid thermoplastic resin. Further, by using the recycling method of thepresent invention, insoluble elements such as thin metal film, such asCu thin film, Ni thin film and the like, thermosetting resin coatingfilm, glass fiber, and inorganic filler can be easily removed.

1-13. (canceled)
 14. A recycled thermoplastic resin material prepared bya method for manufacturing a resin mold comprising; dissolving adiscarded compound resin mold consisting of thermoplastic resinelement(s) being solvent soluble, and element(s) being solventinsoluble, to separate said insoluble element(s), wherein saidthermoplastic resin element(s) has (have) a heat distortion pointgreater than 80° C., said heat distortion point being measured by themethod following ASTMD648 and applying a load 1,820 MPa, evaporating thesolvent from the resulting solution of said thermoplastic resinelement(s) to recover said thermoplastic resin(s) and crushing andremolding said recovered thermoplastic resin(s), and adding recycle aidagent(s) to said solvent soluble recovered thermoplastic resin(s) torecycle said thermoplastic resin(s) as resin mold material.
 15. Arecycled thermoplastic resin material in accordance with claim 14,wherein said recycle aid agent(s) is(are) virgin thermoplastic resinand/or virgin thermoplastic resin having compatibility with saidrecycled thermoplastic resin, and/or a rubber-like material and/or aninorganic reinforcing material and/or an organic reinforcing material.16. A recycled thermoplastic resin material in accordance with claim 14or 15, wherein said compound resin mold is a printed circuit board andsaid solvent soluble thermoplastic resin element is a base board andsaid solvent insoluble elements are thin metal film and thermosettingresin film, formed on the surface of said base board.
 17. A recycledthermoplastic resin material in accordance with claim 14, wherein nonhalogen fire retardant(s) is (are) added to said solvent solublethermoplastic resin element(s).
 18. A recycled thermoplastic resinmaterial in accordance with claim 14, wherein fire retardant(s)containing phosphorus and/or metal hydroxide is (are) added to saidsolvent soluble thermoplastic resin element(s).